1. Field of Invention
This invention relates to nut wrenches, specifically to those used to manipulate wingnuts and drawing holder nuts by hand in an office setting.
2. Description of Prior Art
Wing nuts have been used extensively in the past as a direct interface between mechanical threaded members and the people who use them eliminating the need for other tools. This often comes up in Engineering and Architectural offices where drawing holders need tightening and wingnuts are provided to make the human hand an adequate tool to do the job. The intended design is sufficient to tighten most drawing holders to hold ten to fifteen "blue print" drawings, but many orifice applications require holding as many as 100 to 200 drawings in one drawing holder! This has given rise to a variety of wingnut and drawing holder nut wrenches that in some measure fill the need to provide sufficient tightening to hold the desired number of prints in each print holder. This is further complicated by the introduction of large paper copy machines that can produce large drawings on "plain paper"; which has a much lower coefficient of friction. The reintroduction of tools into the drawing holder picture somewhat defeats the purpose of the wingnuts, but they can still be tightened enough to hold the drawings from moving until the tool can be used to provide full tightening.
U.S. Pat. No. Des. 260,473 issued to B. W. Rust provided a wrench with enough leverage to tighten and twist off or strip the threads of most drawing holder bolts and had the additional disadvantage that it could slip under the wing nut when it was partially loosened.
U.S. Pat. No. 4,685,360 issued to Gaylord W. McCurdy solved the problem of the wrench slipping under the nut, but still gives generally a long lever-arm enabling the user to twist off or strip the threads of most drawing holder bolts with relative ease.
Both of these wrenches can easily scratch the print holders as they tighten them and both leave the socket and wing nut exposed while being used. This style of tool also gives the appearance of being part of a mechanics operation and is somewhat incongruous in the office setting.